I have had two call backs this week for yellowing grass. One had 19-3-6 with Dimension at .75#N/K, don't remember right off how much Dimension, and the other has had no fertilization.

Both were spot sprayed with a backpack with Momentum at 1.0 ounce per thousand with 1/3 ounce sticker and 1 ounce tracker. Both of these lawns now have yellowing, only on some grasses, primarily the creeping red and bluegrasses in the shade. That's the funny thing, it seems like only the grasses in the shade are yellowing. They are quite bright right now, and I am wondering if it will fade with fertilization, or if it will appear more pronounced if the grass around it greens up even more. The full sun lawns I sprayed before and after did not show signs of yellowing, so I can't believe it was just the chemical.

Both lawns test in the mid 6's for pH, one has all high test levels of P, K, Ca, MG, and S, the other, with the Dimension application tests out lower, in the medium range for all nutrients.

Any thoughts on what might have happened or what to do to correct?

Thanks,

EG

tremor

06-13-2003, 08:59 AM

Not sure where you're located. But around here turf is stressing from a lack of sun. Shaded areas will be that much worse. Applying herbicide to stressed turf (ANY kind of stress), may result in discoloration.

I am in south side Virginia, a transition zone, just south of Roanoke, Virginia.

There were no lesions of any kind on the grass, just a uniform pale yellow color.

The lack of sun may well be applicable here too, we have had over 20 cloudy days in May, and much more rainfall than normal.

Also, on the lawn with the Dimension, it had been seeded last fall, but it had been mowed six to eight times before I made the application. I did not know this until after the application had been made. Might this also play a role?

Thanks,

EG

Enviro Green

06-13-2003, 09:31 AM

Steve,

I also sent you a pm, if you get a chance.

Thanks!

grassguy_

06-14-2003, 03:24 PM

As crazy as it may sound have you ruled out any insect activity? I've seen in the past where greenbug aphids will discolor a shaded area severly and often has been misdiagnosed. Just a thought! They'll be found between the crown and root zone usually attached to the roots, but you'll need a magnifying glass.

Enviro Green

06-14-2003, 10:12 PM

I did not see any insect activity, but I will check closer. The funny thing is it was only on two types of grass. Also, the soil test came back deficient in phosphorous for the site with the Dimension application....